In the field of air conditioners, there is known a multi-type air conditioner including a plurality of outdoor units connected in parallel to a plurality of indoor units via refrigerant pipes, respectively.
In this type of air conditioner, the number of outdoor units to be operated is arranged in response to a request of an indoor unit.
However, in a case where an outdoor unit in operation and an outdoor unit during shutdown exist in mixed arrangement, a refrigerant may flow into the outdoor unit during the shutdown from the outdoor unit in operation via a refrigerant pipe, and the refrigerant may stagnate in a liquid tank, which may result in shortage in a circulating amount of refrigerant in a refrigeration cycle.
Accordingly, there is known a configuration in which a shutoff valve is provided between a liquid refrigerant inlet/outlet port and a liquid tank of each outdoor unit, and by fully closing the shutoff valve, the refrigerant is prevented from flowing into the liquid tank of the outdoor unit during the shutdown. There is also known a configuration in which a circulating amount of refrigerant in a refrigeration cycle is adjusted by controlling opening and closing of the shutoff valve.